Portable device for measuring heart rate



FIG. 1 is a top left perspective view from the left side of a portable device for measuring heart rate according to our novel design;

FIG. 2 is a top view thereof;

FIG. 3 is a top side view thereof;

FIG. 4 is a bottom side view thereof;

FIG. 5 is a right side view thereof, the left side view being mirror symmetrical; and,

FIG. 6 is a bottom view thereof. 

The ornamental design for a portable device for measuring heart rate, as shown and described. 